Photos: Spiral Jetty, Robert Smithson's wondrous earthwork

Spiral Jetty

Robert Smithson's Spiral Jetty, one of the world's most famous earthworks, sits on the north side of the Great Salt Lake, near Promontory Summit. The artwork, which Smithson built in 1970, has had an interesting history, including spending years submerged under a sustained higher lake level.

Today, it is fully uncovered, but the thousands of volcanic basalt rocks that make up Spiral Jetty no longer stick up three feet above the salt-encrusted surface of the lake, as they did when the piece was first built.